Production of primary alkyl halides



f orimary halides. which involves the alltylation ofafter all of the allyl chloride had been added.

' and hydmfiuom Emil- The tamper chlorine content of Cal-115C115 26.35%. The probl a was 345 Q M l y, rd, N. 3., aor to Stand Oil velo merit Compare a corporation all Dela No re Application y id, 1948, -1 No. acacia e present invention relates to primary allay] chloride, methallyl chloride, the halogen derivahalides and processes for producing the same, and tives of n-butcne and isoand normal pentene. more culoriy it relates to branched chain etc.

ry alkyl chlorides, The probable formula of preferred compounds It has been known that the preparation of made according to this invention, is as follows:

primary halo derivatives of acylic hydrocarbons is CH: CHZX dimcult. The preparation of the secondary and tertiary alkyl halides is relatively easily achiev- Y able. Thus when a parafin is treated at high h H it temperatures with a halogen such as chlorine. 1 wherexis ahalogen atom.

the chlorine substitutes with greater facility, the without limiting myself to the precise details y r attached to a Carbon atom which is and with the understanding that they are ofiered connected to at least two other carbon atoms. merely by way of m e g 1 t forth below an When S yd fl is lit-Walled 1b0 two specific examples fully disclosing preferred minal carbon atom. When isoparafins are submodificatflgns of my invention jected to direct halogenation. the product 012- E 1 tallied is mostly secondary and tertiary halides. I mmzle Furthermore. when olefins are hydrohalogenated, 2-methyl 3-chlormethy1 pentane was prepared the reaction normally follows Markowniirofls as follows: 3 mole of isobutane were mixed with Rule that-the halogen adds to the unsaturated 2 about 62.5 weight percent of chlorsulfonic acid carbon atom hearing the least hydrogen atoms catalyst (based on the isobutane) and the mixt'vith the result that secondary and tertiary ha-L- ture was cooled to about 45 C; Que mol of ides are produced, rather than the primary halallyl chloride was slowly added during a period ides. of one hour while constantly stirring the mix- 3 have now discovered a method for producing 2 ture. The stirring was continued for two hours isopara'mns or other compounds containinl; a ter- The mixture was permitted to stratify into a lower tiary hydrogen with a halogenated derivative of catalyst layer and an upper oily layer. The upper an olefin. By means or this process a. number of layer was separated by decantation and subnew compounds have been prepared, iorexample, 36 jected first, to distillation to remove the excess 2=mcthyi d chlorrnethyl pentane by the alkylaisoloutane and then to a further distillation. In

tion of isobutane with allyl chloride. the second distillation, a large portion (as much lrcllortant features of my invention are the use as 75%) of the product boiled at 147 C. which of low temperatures, and oi alkylation catalysts indicated selective alkylation. The 14*? C. fracwhlch are highly active at the low temperatures, tion had a bromine number of on and a specific thus avoiding polymerization, crackin dehydrogravity of cases lonlogenation and isomerization of the primary halide product to secondary and tertiary halides. r

suitable catalysts We chlorsulfomc fiuorsul and contained 26.45% chlorine. The calculated ture should preferably be below 0? C.; good results 11 have been obtained as low as --70 C. The preable formula of t e heptyl alum as is ferred range is from -eo to 50 (3., however,

i using chlorsulfonic acid as a catalyst. cHrcHcH-cn=-cm it is also important to use a halogenated oleas shown by the following tests; 'finl feed Stoc cont the halogen in a pri- First, the above compound was not convertposition, if primary halides are to be obed to an alcohol by refluxing for live hours with tained. Further, the halogen is substituted in a aqueous KOH. It was not converted to an alcomethyl group rather than in the olefinic CH2= hol by treatment with moist silver oxide. It was group. The specific isoparafins and olefin derivnot converted to an olefin by refluxing for 3.5 etives employed, of course, denend on the specific hours with butyl alcoholic KOH. It was not conproducts desired. Suitable reactants containing verted to a paraffin by reduction with zinc and a tertiary hydrogen are lsobutane, isopentane, hydrochloric acid. The above negative tests inlsohexane and methyl cyclohexane, etc., while dicate strongly that the chlorine is attached to a suitable halogenated olefinic reactants are aliyl primary carbon because if it were attachedto a aaczces secondary or tertiary carbon atom it would certainly have responded to the above tests. The aqueous KOH had no effect whatever, while the alcoholic KOH converted the compound to an ether. In order to determine the carbon structure of the compound, it was converted to a paraffin by reacting with magnesium in ether solution and hydrolyzing the resulting Grignard reagent with dilute HCl at C. The paramn was identified as 2,3-dimethyl pentane by means of its boiling point (89.7 C.) and specific gravity. The heptyl chloride was also converted to an alcohol by means of the Grignard reaction, by exidizing the Grignard reagent with dry oxygen prior to hydrolyzing with dilute HCl. The alcohol boiled at from 165-166.5 C. at 1 atmosphere pressure, and at 11-72" C. at 17 mm. and had a specific gravity of 0.836. The alcohol was oxidized by means of chromium oxide to an acid boiling between 203 and 210 C., which was converted to the acid chloride and then to the amide which melted at 135 C. This smelting point corresponds with the value given for the melting point given in the literature (Jour. Chem. Soc. 77, 91) for ethyl isopropyl acetamide:

CH CONH:

CHs- E-CH-CHz-CH:

indicating that the heptyi chloride prepared by the alkylation of isobutane with allyl chloride is Z-methyl 3-chlormethyl pentane.

Example 2 all of the methallyl chloride had been added.

The amount of catalyst was thesame as in Example 1 and the temperature wasmaintained at about 45 C. The main products were isobutyl chloride, dichlor isobutane and a branched chain octyl chloride. The boiling point of the octyl chloride was about 157 C., which difierentiates it from any previously reported octyl chloride. While the exact structure of the octyl chloride has not yet been determined, it is indicated that the chlorine is attached to a primary carbon of a branched structure.

The principle of my invention may be applied to the production of a large plurality of primary halogenated alkyl compounds by means analogous to those disclosed above. The foregoing specific examples are merely illustrative and do not impose any limitation on my invention, and obviously any desired halide may be made by 8.1- kylation of the proper halogenated olefin with an isoparaifin.

The amount of halogenated sulfonic acid (which acid may be chlorsulfonic acid, fluorsulionic acid, etc.) used in my process may vary from A to 2 parts by weight of acid per part of isoparafiin. Further, the ratio of isoparamn to halogenated olefin in the reaction mass may vary from 1 to 100 mols of isoparaflin per mol of the olefin, but the isoparafiin is preferably employed in molecular excess over the said olefin.

My present invention provides means for the production of high boiling alykyl chlorides, fluorides and bromides wherein the halogen is attached to a primary carbon atom. which halides a are highly stable against hydrolysis. dehalogenation, isomerization and reduction. The products find especial use as high boiling solvents, and as intermediates in the production of branched chain alcohols, ethers of high octane number and esters, and of many useful compounds not otherwise obtainable except by expensive laboratory methods such as the Grignard reaction.

Numerous modifications of my invention may be made by those familiar with the art without departing from the spirit thereof.

What 1 claim is:

1. Method of producing primary halogenated hydrocarbons, which comprises reacting an olefin, halogenated in a primary position, with an isoparamn in the presence of a catalyst consisting of halosulfonic acid under alkylation conditions, at a temperature between about 0 C. and about 70 C.

2. Method according to claim 1, in which a chlorsulfonic acid is used as the catalyst.

3. Method according to claim 1, in which'a chlorsulfonic acid is used as the catalyst and the temperature is between about -40 and about 0 C.

4. Method according to claim 1 in which the reaction is carried out at a temperature between about -40 C. and about 70 C.

5. Method according to claim 1 in which the isoparafiin is present in molecular excess with respect to the halogenated olefin in the reaction mass.

6. A process which comprises reacting isobutone with ailyl chloride in the presence of a catalyst consisting of halosulfonic acid at a temperature between about 0 C. and about -70 C.

7. A process according to claim 6 in which the temperature of the reaction is maintained at about 45 C. and in which the catalyst is chlorosulfonlc acid.

8. A process which comprises reacting isobutone with methallyl chloride in the presence of a. catalyst consisting of halosulfonic acid at a temperature between about 0 C. and about 70 C.

9. A process according to claim 8 in which the temperature is maintained at about 45 C. and in which the catalyst is chlorosulfonic acid.

. JOHN C. MUNDAY.

REFERENCES CITED The following references are of recordin the file of this patent:

UNITED STATES PATENTS istry," vol. 32, page 182 (1940).

Chem. Abstracts." vol. 27, pages 4770-1 (1933), abst. of article by Soday et al. in J. Am. Chem. 800., vol. 55, pages 3293-302 (1933).

Ibid., vol. 26. page 426, (1932), abstract of or- (Other references on tollowin: page) OTHER REFERENCES tlcle by Braun et al. in "Ann, vol. 490, pages 179- 88 (1931).

- Ibid., vol 26, page 1246 (1932), abst of article by Braun et a]. 1n "Ber., vol.- 64B, pages 2617-21 (1931).

Ib1d., vol 25, page 4845 (1931), abstract of article by Levene et al. in pages 405-18 (1981).

J. Biol. Chem," vol. 91,.

- v .6 vIb1d.. vol. 30,- 001. 79-80 (1936), abstract of article by Levene et al. in "J. Biol. Chem, vol. 111, Pages 299-312 (1935).

Ibid., vol. 33, col. 972 (1939), abstract of article 5 by Houston et a]. in "J. Org. Chem," vol 3, pages Beil steln, Handbuch der Chemie," vol. 1, pages 157-8.

Organischen 

